Recording phonograph



Ra HASE I RECORDING PHONOGRAPH Nov10,1925" 1 A1,560,686

Fi1dFeb.18, 1921 I zsheewsneet 1 III- ` Vture is mounted; In articular the armature The p1vot"5 1s formed by a block 16 upon Patented Nov. 10, `19,25. i

- `UNITED STATES PATENT OFFICE.. y

RUDOLF E AsE, or .'RERLIN, GERMANY,

AssreNoR, BY MEsNE AssIeNMENTs, y To NAM-EoozEf--.vENNooTscnAr rrNENzIEEEEDMAATseHA-rrr DRIEBERGENQ or i AMSTERDAM, NETHERLANDS, A COMPANY or yTHE NETHERLANDS.

RECORDING rEoNoeRArn.

Application mea February 18, 1921. serial No. 446,201.

W. 4.8, Germany, have invented new and useful Improvements in Recording Phonographs, of which the yfollowing isA a'speciication. 'f j The diaphragm of a telephonie sound-box for dictating phonographs, telephonographs and like apparatus, is subject, as is well known, to various stresses.; the continuous pull of the permanent magnet bends the diaphragm towards the poles; the pressure of vthe stylus against the cylinder transmits through the attached lever mechanism an opposlte pull on the diaphragm;4 the 1mechanical4 vibrations of thev diaphragm resulting from the electric current ripples are produced by a constantly alternating stress; `and finally there is an inertia impulse which arises in consequence of the current impulse. ,The dia hragm cannot ,for long respond entirely e astically. tothe joint effect of all these s'trestes'iv and a permanent deformation occurs This deformation ves'rise to resonanceeifects in the vibrations of thel diaphravm, whichr deteriorate the action of the soun v-,boxuii'til it iswlhollyf unusable. The

v subject of the present, invention'fis fa Asoundbox in which 'these faults are' obviated by 'replacing the diaphragm by an armature mounted in front of the magnet poles., which is coupled in the usual way withthle Iends of fthe inscribing lever mechanisms, Such `ref placement,o; the diaphragm by anarmayture is yiupzcci'npanied Awith other striking ad'- vantageS,v dependent on the way the'ama- 'may be tuned to a de nite hatural frequency,

by which means, when thedictatingphono-- graph or telephonograph A,1s used/ as'a re-v ceiving apparatusin wireless telegraphy, it

is possible-to tune;to,.aJI denitesender.. p

y adjustment of the armature, ,ap ropriate damping due to-.the'ymagnetic eldmay be obtained. The aircushion between the poles and armature also has a damping effect. v But this damping is dependent on the distance of the armatureffrom the polea@y another -means of obtaining'good damping,

whichl consists in bringing to bear on the armature more or vless elastic bui'ers which are capable of adjustment'.I may be variously arranged in relation to the armature, according to the shape and mounting of the armature with respect' to the magnet poles. I

In the drawings three examples ',of the invention are illustrated.,` l

Figures 1 and 2 show one constructionr side and`front views respectively.

Such a bufferl .Figures 3 and 4.are side elevation and plan'from underneath respectively of a second construction, andv J Figures 5 and 6 are lviews similar to Figures 3 and 4' of a third construction.`

The powerful permanent magnet system 1 carries on its poles. 2 the coils 3, through.,

which the current ripples flow. The armature4 is mounted in front of the poles ,2 after theashion of la 1beam upon two sup ports lloaded with a'single load. The two supports may be alike or di1ierent; itis s` vsential "that .the armature, swhich isnt be bent by the magnetic pull as its single load,

shall be heldfat as small 'a distancel from the po1es'2'as possible.` By way/of example Figure 2 shows the1 armature 4 pivotally vao mounted at one end at 5, while at the1 other end a more or less flexiblertongue 6 is at-,Y

tached to it which bearsa-gainst a stop 7 This is to ensure that the armature yshall not4 rock @bent amend, .as ha .pesan relay or an electric bell; but shalIl) only vibrate. by bending, like a' beam on two supports. The pivot 5 may be replaced by a stop 7 as at the otherend, but the pivothas the advantage that ,it su presses twisting "of the farmature transverse y to its length.1 A

which thearmature 4 is fastened between of a knife-edge kor point A18, a ,ainst' which` y'thelendof the1tongu'ef6 liesl n order that the armature 4 may be adjusted rto a greater or less distance from the magnet poles 2 "the 'lmifeledge or vpoint y 18 has 'an adjusting device, `which may be constructedin'anyde` sired manner. For instance, as may be seien from Figure 2thestem of the.l point 18 may be screwed more orless into the block 19, by which means the distance between the armature`4 and the poles 2 is altered.

The inscribing lever mechanism is mount# ed transverfs'ely'v tothe armature 4, and con,- sistsin known manner of a lever' 9 mounted on the blocklS which serves to takeup the I'ui'idulations of the phonograph cylinder.

The actual inscribing lever is pivotally Zconnected with this lever at 11. IUpon one end is the stylus 1\2,while the other is engaged by a pull rod 13 which couples the inscribing lever 10 with thearmature 4. The, coupling rod v13 is pivoted to the-armature 4 at 14 as near as possible tethe pointl of application of the magnetic pull. "To support the ,whole soundbox the block 15 is attached.l tothe slid by ersed aloiihe cylinder; this is not illusv j trated as its construction is known.

which the sound-box is trav- The action of the armature is such that in consequence of ltlfie.magnetic pull it bends' v as a beam upontwo supports witha single load. Since the magnetic force is overwhelmingly'` stronger` than the pull of the suspended inscri'bing lever. system the' stress due to the inscribing lever can be neglected.

" The armature suii'ersbending by the magnetic force, .and this bending varies in consequence of the current ripples in the current exciting the electromagnet, and is transmitted tothe inscribing lever system so that the stylus inscribes the sounds received ini the' phonograph cylinder. To increase thesensi` tiveness the stop 7 should be so adjusted that the distance of the armature l4 from the` magnet poles 2 is small as out causing dangerr of sticking.

In order to regulate the' ripples the tongue 6 `may be designed of greater or less flexibility. Foithe reception of speakin currents itis desirable "to use an l@other frequencies ina armature aving anatural frequency faitv abovethe frequencies of speech. At the same time the armature should .be-damped as ,well-.arsfpossible inf orderl still ,further to .I 'atten y. thai/resonance curve. fraai' efe-.y

\m`eans -oftuning a telephonograpli serving as a receiving apparatus to a definitesender,

so that only the signals given by it-are -received. f

Various means mayl be employed to time t thearmature 4 to a1 definite frequency. It is desirable to design the sound-,box from the outset'for a certain range of frequencies,` and to effect fine tuningwithin these limitsby adjustment. y-T.o adapt the sound-boic`for frequencies beyond this range, 'the :tongue 6 may designed of `different stiinessj say by alteringits thickness or width, or the' knife-edge or point 18 of the stop 7 ,may be possible withn l bending of. the armature in' a definiterelation to the current replaced by a. atvsurface. Finer tuning may be obtained by adjustment of the stopv 7 so as to bring the 'armature 4 more orless near the poles 2, the effect being` that the danipingby .themagnetic field is altered.

Othei known means of damping may also be employedms requiredzfor insta-ncemecha-nicaldamping by which themovements of the armature are directly dampedf The naturalpfrequency `may also `be varied byy lengthening 'or shortening the armature by lateral shifting of the sto 7 ,for which pnrpose the`block 19 shoul be provided with 2O extending beyond its support at the opposite end frointhe tongue 6.' Where a.

an adjusting device for shifting it laterally." In the construction illustrated infFigures; I3 and 4 the armature 4 has a prolongation pivot support is'j' used' this prolongation should be at the' pivot end. A 4bul'er 21 is arranged tobear on this prolongation. This buffer 'comprises a foot or socket 22, in which the stem 23 of a cup 24 is adjustablymounted; for instance `the stein may be threaded.

In the cup is a soft block'25, which by suit# able adjustment of 'the' cup, can bev made to` bear l gently against the prolongation 20. Such adjustment of the bulfer causes damping in the` sense that it suppresses the naturalvibiations of the armature, while other vibrations due to the current ripples are rendered aperiodic. i

other side of the armature prolongation 20, so that it bears.; in the opposite direction upon the armature, with however, substan- The buffer21'may. be arranged on ythe i tially the same effect.; The essence of the arrangement is the interposition of resilient" material between any point `on the armaturev and a lixedpart, sodas to damp the natural'l Joscillations of the armature.

Another constructionv of the buffer,`

shownl in `Iigures I5 and 6. This is mounted upon a bridge 26 spanning themagnet-.and

armature, and bears upon the back of thel armature. As before it consists of `the stem 23, the cup 24, and the soft inlay '25. The

`socket 22 within which' the stem 23 is adjustable is secured inside the bridge.

The same end may be attained by checking 'j bythe aid of a damping buiier'not the ar'm'ature itself but a part fixed to it. For iri- 4 stance the coupling rod 13 operating the insciibing lever system, instead of being linked to the armature, vmay be secured rigidly to' it by a screw 29, and may pass between cork cushions, as indicated at '28 in Figure 3.

Such cushions mayfor instance be mounted'. 4on a bridge like 26. l x

` What lclaiml is: l f

In sound recordingapparatus'the coinbination with a magnet core of windings.

"to carry seakingcurrent, a bar' armature .i

e` poles of said. magnet, a resilient tongue rigidly secu-red to said armature and forming a prolongation thereof2 supports, one bearing upon said armature and one uponsaid resilient tongue sustaining said armatureiagains't the attraction of said magnet,`an inscribing lever mechanism anda connection between said lever mechanism and said armature.

,2. In sound recording apparatus the com# bin-ation with a magnet core of windings to carryy speakingcurrent, a bar' armature adjacent the poles of said magnet, a pivotal nection between said lever support-at one end o'f-said armaturea yresilient tongue attaclie'dtothe other end of said larmature,an adjustable abutment for said, tongue tol support the' armature against the magnetic pull, an insoribiirg lever mechanism and a connection between said lever mechanism and said bar armature.

3. In sound recordingjapparatus the combination with a magnet core of windings to carry speaking current, a bar armature adjacent the poles of said magnet, a re- -silient tongue attached to and prolonging said armature, supports,Y one bearing upon f said armature and one upon said resilient jacent to the eiective to carry, speaking current, a bar armature adjacent the poles of said magnet, a pivotal supportat one end .of said armature, a rey silienttongue attached to the other end of said armature, an abutment for said tongue tol support the armature against the maganetic pull, an inscrihing lever mechanism and a connection dbetween sald lever mechanlsm and said bar armature.;

5; In sound recording apparatus the com bination with a magnet coreof windings to carry speaklng current, an armature'adjacent tothe poles of said magnet, means.

, for tuning said armature to a particular :fre-

quency ofv oscillation, an inscribing lever mechanism,V and a connection between said lever mechanism and sald bar armature adot the magnetic pull.

6. In a sound recording apparatus the :combination with a magnet core of windings to carry speaking current, a bar armature adjacent the poles of said magnet, a resilient ftongue secured directly to said armature; supports bearing respectively said armature and said tongue and sustaining 'said armature against-the attraction of said magnet, a pivoted stylus carrying lever, and a link connecting said lever directly with saidA armature;

In testimony whereof I have 'signed my name to this speciication.

` RUDOLF HASE.

point of application eol 

